Web App Security Scanners Compared: Free vs Paid in 2026

If you're shipping a web application, you need to scan it for vulnerabilities. The question is which tool to use. Here's an honest breakdown of what's available in 2026.

Free Tools

Mozilla Observatory

What it checks: HTTP security headers (CSP, HSTS, X-Frame-Options, etc.)

What it misses: Everything else. No XSS detection, no API scanning, no dependency checks, no authentication testing. It's a header checker, not a security scanner.

Best for: A quick sanity check on your security headers configuration.

SecurityHeaders.com

What it checks: Similar to Mozilla Observatory — HTTP response headers.

What it misses: Same gaps. Headers are important but they're only one layer of defense.

SSL Labs

What it checks: SSL/TLS configuration, certificate validity, cipher suites, protocol support.

What it misses: Everything above the transport layer. Your SSL can be perfect while your application leaks data through XSS.

Best for: Verifying your SSL configuration after setup.

OWASP ZAP

What it checks: Comprehensive — injection, XSS, CSRF, authentication issues, and more.

What it misses: Requires setup, configuration, and security expertise to interpret results. Not practical for "scan and fix in 5 minutes."

Best for: Security professionals who want a free, full-featured DAST tool and have time to configure it.

Nuclei (ProjectDiscovery)

What it checks: Template-based vulnerability scanning. Thousands of community-contributed templates for CVEs, misconfigurations, exposed panels, default credentials, and technology-specific issues.

What it misses: No guided remediation. Results require security knowledge to prioritize and act on. Template quality varies. Can be noisy with false positives on certain templates.

Best for: Developers comfortable with CLI tools who want broad vulnerability coverage for free and can write their own automation around it.

Nikto

What it checks: Web server misconfigurations, outdated server software, dangerous files and programs, version-specific problems.

What it misses: Modern application-layer vulnerabilities. Primarily focused on server configuration rather than your application code. Doesn't understand SPAs or modern JavaScript frameworks.

Best for: Quick server-level reconnaissance. Good complement to application-level scanners.

Paid Tools

Snyk

What it checks: Dependency vulnerabilities, container security, IaC scanning.

What it misses: Runtime vulnerabilities, security header misconfigurations, API-level issues. Focused on code and dependencies, not the running application.

Cost: Free tier covers basic dependency scanning. Team plans start at $25/developer/month. Enterprise pricing is custom.

Best for: Teams that want dependency scanning integrated into their CI/CD pipeline.

Burp Suite Professional

What it checks: Everything. It's the industry standard for web application penetration testing.

What it misses: Nothing — if you know how to use it. The learning curve is steep, and it costs $449/year.

Cost: $449/year per user for Professional. Enterprise edition is significantly more.

Best for: Professional penetration testers and security engineers.

Detectify

What it checks: External attack surface management, OWASP Top 10 vulnerabilities, subdomain discovery, continuous monitoring.

What it misses: Internal application logic, dependency vulnerabilities, code-level issues. Focused on the external attack surface.

Cost: Starts at around $275/month for a single application. Surface Monitoring starts at $190/month for up to 10 root domains. 14-day free trial available.

Best for: Companies with multiple subdomains and external-facing services that need continuous monitoring. Overkill for a single SaaS app.

Intruder

What it checks: Network-level and web application vulnerabilities. Covers OWASP Top 10, infrastructure misconfigurations, and emerging threats. Integrates with cloud providers (AWS, GCP, Azure) for perimeter scanning.

What it misses: Deep application logic testing. Better at finding known vulnerability patterns than business logic flaws.

Cost: Essential plan from $113/month (billed annually). Pro plan from $181/month. Free 14-day trial.

Best for: Small teams that want a managed scanner covering both infrastructure and web application vulnerabilities without the setup overhead.

HostedScan

What it checks: Runs open-source tools (OpenVAS, OWASP ZAP, Nmap, SSLyze) as managed cloud services. Network scanning, web application scanning, SSL checks, and port scanning.

What it misses: Advanced application-level testing. Since it wraps existing open-source tools, it inherits their limitations. No custom remediation guidance.

Cost: Free tier includes 3 targets and limited scans. Premium starts at $59/month for 20 targets. Professional at $149/month for 60 targets.

Best for: Developers who want the power of tools like ZAP and OpenVAS without managing the infrastructure to run them. Good value for the price.

Astra Security

What it checks: Automated DAST scanning covering OWASP Top 10, API security testing, business logic testing, and compliance checks (GDPR, SOC 2, ISO 27001). Includes a pentest dashboard with human verification.

What it misses: Dependency scanning (you'll still need Snyk or npm audit for that). Some advanced business logic issues still require manual testing.

Cost: Scanner plan from $199/month. Pentest plans (which include manual verification) from $999/month. Annual discounts available.

Best for: Startups that need a compliance certificate for enterprise sales and want combined automated + manual testing.

Vercel Security (built-in)

What it checks: Basic protections — DDoS, bot protection, firewall rules.

What it misses: Application-level vulnerabilities. It protects the infrastructure, not your code.

Cost: Included with Vercel plans. WAF and advanced protection on Pro ($20/mo) and Enterprise plans.

Best for: Vercel users who want platform-level protection alongside application scanning.

Detailed Comparison Table

Here's a side-by-side comparison of every scanner mentioned above across the criteria that matter most:

| Tool | Type | OWASP Top 10 | API Scanning | Dependency Check | Headers/SSL | CI/CD Integration | Remediation Guidance | Scan Speed | Starting Price | |------|------|:---:|:---:|:---:|:---:|:---:|:---:|:---:|:---:| | Mozilla Observatory | Free | Partial | No | No | Headers only | No | Minimal | Instant | Free | | SecurityHeaders.com | Free | Partial | No | No | Headers only | No | Minimal | Instant | Free | | SSL Labs | Free | No | No | No | SSL/TLS only | No | Yes | 2-3 min | Free | | OWASP ZAP | Free DAST | Yes | Yes | No | Yes | Yes (plugin) | Minimal | 10-60 min | Free | | Nuclei | Free DAST | Yes | Partial | No | Yes | Yes (CLI) | Templates | 5-30 min | Free | | Nikto | Free | Partial | No | No | Partial | Yes (CLI) | Minimal | 2-10 min | Free | | Snyk | SCA/SAST | Partial | No | Yes | No | Yes (native) | Yes | 1-5 min | $25/dev/mo | | Burp Suite Pro | DAST | Yes | Yes | No | Yes | Yes (API) | Yes | 30-120 min | $449/year | | Detectify | DAST/ASM | Yes | Partial | No | Yes | Yes (API) | Yes | 30-60 min | ~$275/mo | | Intruder | DAST/Infra | Yes | Yes | No | Yes | Yes (API) | Yes | 15-60 min | $113/mo | | HostedScan | Managed OSS | Yes | Partial | No | Yes | Yes (API) | Minimal | 15-45 min | $59/mo | | Astra Security | DAST+Pentest | Yes | Yes | No | Yes | Yes (API) | Yes (human) | 30-90 min | $199/mo | | Vercel Security | WAF/DDoS | No | No | No | Partial | Built-in | No | N/A | Included | | CheckVibe | DAST | Yes | Yes | Yes | Yes | Yes (API) | AI-powered | 30 sec | $19/mo |

Cost Breakdown: What You'll Actually Pay

Let's be real about costs. Here's what a typical indie hacker or small team would pay annually for each option:

Free tier (cobbling together free tools):

• Mozilla Observatory + SSL Labs + npm audit + OWASP ZAP
• Cost: $0
• Time cost: 2-4 hours/month to run, interpret, and cross-reference results
• Coverage gaps: No API scanning, no AI remediation, no continuous monitoring

Budget tier ($200-$700/year):

• CheckVibe Starter ($228/year) or HostedScan Premium ($708/year)
• Good coverage for a single SaaS application
• CheckVibe adds AI-powered fix suggestions and 30-second scans

Mid-range ($1,000-$3,000/year):

• Intruder Essential ($1,356/year) or Snyk Team ($300/dev/year for a 3-person team)
• Better for teams with infrastructure scanning needs
• Snyk shines for dependency management but doesn't cover runtime vulnerabilities

Enterprise ($3,000+/year):

• Detectify ($3,300+/year), Astra ($2,388+/year), or Burp Suite Enterprise
• More than most indie hackers need
• Makes sense when you have compliance requirements or enterprise customers

The sweet spot for most indie hackers is the $200-$700/year range. You get automated scanning, actionable results, and enough coverage to catch the real issues without the overhead of enterprise tools.

What Indie Hackers Actually Need

After talking to hundreds of indie hackers about their security setup, here's what consistently matters and what doesn't:

What matters:

1. Speed. If a scan takes 30+ minutes, you won't run it regularly. You'll run it once, fix some things, and forget about it. You need results in under a minute to make scanning a habit.

2. Actionable results. A report that says "XSS vulnerability found at line 47" is useful. A report that says "137 potential issues found" with no context is just noise. The best scanners tell you what's wrong, why it matters, and how to fix it.

3. Coverage of your actual stack. If you're running Next.js on Vercel with Supabase, you don't need a tool optimized for scanning Java EE applications behind an F5 load balancer. You need something that understands modern JavaScript frameworks, serverless functions, and BaaS platforms.

4. Price proportional to your revenue. Spending $275/month on a security scanner when your MRR is $500 doesn't make sense. The tool should cost a fraction of what you're making.

5. CI/CD integration or API access. Scan on every deploy, not when you remember to. This is the only way to keep security from becoming technical debt.

What doesn't matter (for most indie hackers):

• Compliance certificates. Unless you're selling to enterprises that require SOC 2 or ISO 27001, you don't need a scanner that produces compliance reports.
• Network infrastructure scanning. If you're on Vercel/Netlify/Cloudflare, the platform handles infrastructure security. You need application-level scanning.
• Manual pentest add-ons. Valuable for funded startups, overkill for a solo SaaS doing $5k MRR.
• Agent-based scanning. Requires installing software on your servers. If you're serverless, this doesn't apply.

What to Look For

When choosing a scanner, ask:

1. What does it actually scan? Headers-only tools give false confidence. You need injection testing, authentication checks, and API scanning.
2. How fast is it? If a scan takes 30 minutes, you won't run it often. Speed matters for habit formation.
3. Can you fix what it finds? A report with 200 findings and no remediation guidance is just anxiety in PDF form.
4. Does it fit your workflow? CI/CD integration, API access, and IDE plugins reduce friction.
5. What does it cost? Enterprise scanners at $10k+/year are overkill for indie hackers. Free tools miss too much. The sweet spot is in between.
6. Does it understand your stack? A scanner built for Java Enterprise won't catch Supabase RLS misconfigurations or Next.js-specific issues.
7. How are results prioritized? You want critical issues flagged first, not buried in a list of 200 informational findings.

For more on evaluating scanners, see our Website Security Scanner Comparison and our guide on What is Website Security Scanning.

The Gap CheckVibe Fills

Most scanners fall into two categories: free but limited, or comprehensive but expensive and complex.

CheckVibe sits in the middle — 100+ security checks covering headers, SSL, XSS, SQL injection, CORS, CSRF, API keys, dependencies, and more. Results in 30 seconds with AI-powered fix prompts. Plans starting at $19/month.

We built it because we were shipping vibe-coded apps ourselves and needed something between "check my headers" and "hire a pentester."

Specifically, CheckVibe was designed for the indie hacker workflow:

• 30-second scans so you can run one before every deploy without slowing down
• AI fix suggestions that give you code you can copy-paste, not vague advice
• Site crawling that discovers your pages and API endpoints automatically
• Stack-aware scanning that knows about Next.js, Supabase, Firebase, Vercel, and the tools you actually use
• API and MCP server access so you can integrate scanning into your CI/CD pipeline or AI coding workflow
• PDF export for when a client or investor asks "how secure is your app?"

Our Recommendation

Use multiple tools. No single scanner catches everything:

1. Run SSL Labs once to verify your certificate setup
2. Run a comprehensive scanner (like CheckVibe) on every deploy
3. Run npm audit in your CI pipeline for dependency vulnerabilities
4. Get a professional pentest before major launches or when handling sensitive data

Security is layers. Each tool adds a layer.

For a deeper dive into checking your site's security posture, read our guide on How to Check if a Website is Secure. And if you want to understand the scanning process itself, see What is Website Security Scanning.

FAQ

Do I need a paid security scanner?

It depends on what you're building. If your app handles user authentication, stores personal data, or processes payments, a paid scanner will catch issues that free tools miss — things like API endpoint vulnerabilities, CORS misconfigurations, CSRF issues, and authentication weaknesses. Free tools like Mozilla Observatory and SSL Labs cover headers and SSL well, but they're blind to application-layer vulnerabilities. If your app is a static marketing site with no user data, free tools are probably fine. For anything with a login page, a database, or payment processing, a paid scanner pays for itself the first time it catches a vulnerability before an attacker does.

Is OWASP ZAP good enough?

OWASP ZAP is an excellent tool with genuine depth — it can find injection flaws, XSS, CSRF issues, and more. The challenge is usability. ZAP requires installation, configuration, and meaningful security expertise to interpret results. A full active scan can take 30-60 minutes and produces raw technical output that assumes you know what to do with it. If you're a security professional or have the time to learn, ZAP is hard to beat for the price (free). But if you're an indie hacker who needs to scan, understand results, and fix issues in 15 minutes between feature sprints, a tool with better UX and guided remediation will serve you better in practice. Many developers start with ZAP, get overwhelmed by the output, and stop scanning entirely — which is worse than using a simpler tool consistently.

Can I use multiple scanners?

Absolutely, and you should. Different scanners have different strengths. SSL Labs is the gold standard for TLS configuration but doesn't look at your application code. Snyk excels at dependency vulnerabilities but won't find XSS in your templates. OWASP ZAP does deep application testing but misses dependency issues. A practical multi-scanner setup for indie hackers looks like: (1) a comprehensive DAST scanner like CheckVibe for application-level issues on every deploy, (2) npm audit or Snyk in your CI pipeline for dependency vulnerabilities, (3) SSL Labs once after setting up your domain, and (4) a manual security review before major launches. The key is making scanning automatic so it actually happens. One scanner that runs on every deploy is better than five scanners you run once a quarter.

What's the best free security scanner?

For the broadest free coverage, OWASP ZAP is the most capable option. It covers OWASP Top 10 vulnerabilities, supports active and passive scanning, and has an API for automation. But "best" depends on your context. If you just want to check your security headers in 10 seconds, Mozilla Observatory is perfect. For SSL configuration, nothing beats SSL Labs. For dependency vulnerabilities in JavaScript projects, npm audit is built right into your toolchain. Nuclei from ProjectDiscovery is gaining traction for its template-based approach — especially useful if you want to check for specific CVEs or misconfigurations. The honest answer is that no single free tool gives you comprehensive coverage with a good developer experience. Free tools either cover one narrow area well (headers, SSL, dependencies) or cover broadly but require significant expertise (ZAP, Nuclei). That's the gap that affordable paid tools aim to fill.